Researchers take a peek behind puppy dog eyes

In this Monday, April 15, 2019, photo, a dog is seen at Dog Smile House Clinic in Songkhla, southern Thailand. “Survivor” the dog is safely back on land after being found by oil rig workers swimming about 135 miles from shore in the Gulf of Thailand. Chevron Thailand worker Vitisak Payalaw posted on Facebook that […]

Researchers believe dogs use eye muscles to communicate with humans.

The new study suggests that over thousands of years of dog domestication, people preferred pups that could pull off “puppy-dog eyes.”

This preference encouraged dogs to develop the facial muscles needed to create that signature look and get humans to feed or care for them.

Today, dogs use the muscle to raise their eyebrows and to create the sad look. A muscle that does not really exist in their ancestors, the wolves.

“You don’t typically see such muscle differences in species that are that closely related,” said Anne Burrows of Duquesne University in Pittsburgh, an author of the study released Monday by the Proceedings of the National Academy of Sciences.

Burrows and her colleagues found that dogs have a meaty eye muscle to lift their eyebrows, but in wolves, the same muscle was stringy or missing.

In addition to more expressive faces, dogs differ from wolves with smaller snouts and heavily relying on human eye contact.

Dogs use eye contact to know when someone’s talking to them or when they can’t solve a problem, like hopping a fence or getting out the door.

The researchers believe dogs, over their relatively short 33,000 years of domestication, used eye muscles to communicate and people, perhaps unwittingly, obliged.

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